US Masters Swimming chief executive Rob Butcher revealed the organisation is not covered by the same anti-doping rules used by USADA, therefore enabling Armstrong to compete.

However, US Masters Swimming is supervised by FINA - the international swimming federation - which in turn is covered by USADA rules, and was pushing to block Armstrong from competing. Rule 15.1 of the USADA code says any athlete convicted of doping offences is not allowed to take part in sanctioned competitions.

FINA wrote to USMS, and said in a statement: "Therefore, FINA wrote a letter to the US Masters Swimming (with copy to US Aquatic Sports and USA Swimming) requesting not to accept the entry of Mr. Lance Armstrong in the above mentioned competition."